Indiaita



C. D. JENNEY.

SHOCK ABSORBER FOR MOTOR VEHICLES.

APPLICATION FILED -OCT- 6, l9l6.

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IIIIHH CHARLES D. JENNEY, 0F INDIANAPOLIS, INDIANA.

SHOCK-ABSORBER FOB, MOTOR-VEHICLES.

Specification of Letters Patent.

Patented Nov. 18, 1919.

Application filed October 6, 1916. Serial No. 124,177.

To all whom it may concern:

Be it known that 1, CHARLES D. JnNNnY, a citizen of the United States, residing at Indianapolis, Marion county, and State of Indiana, have invented and discovered certain new and useful Improvements in Shock- Absorbers for Motor-Vehicles, of which the following is a specification.

My invention relates to shock absorbers for motor vehicles and its objects are to provide a combined liquid and pneumatic device for checking the relative movement of body and axle which shall be effective in construction; which shall be gradual and easy in its checking movement and which is so arranged as to check the movement of the car body only in the rebound action thereof, thereby permitting the free action of the main springs during the approaching movement of the axle and body; to provide means whereby the device is inoperative in respect to its checking movement upon slight shocks and jars both in the approaching movement of the car body and axle and in the separating movement thereof, thus permitting the springs to have their free normal play for both cushioning the initial shock and checking the rebound while the car is running over smooth roads and subject to only slight jars; to provide means whereby the pressure created by the checking movement of the device will be exerted only against that end of the dash-pot which is opposite to the end carrying the stuffing-box for the piston-rod, whereby the danger of forcing the liquid through the stuffing-box or the necessity for employing a complicated and expensive form of stufl'- ing-box to prevent such escape of the liquid, is obviated; to provide means auxiliary to the arrangement just described to insure against the escape of the liquid. past the piston rod;to provide means whereby the relative reciprocation of the piston and dash pot cylinder in a straight vertical line is obtained; to provide means adapted to yieldingly accommodate the device to side sway or other angular relative movements of the body frame and axle; to provide means for taking up lost motion at the points of flexible connection and to generally improve the construction of a device of this class.

With these objects in view, my invention is embodied in preferable form in the con struction and arrangement hereinafter described and illustrated in the accompanying drawings.

In these drawings, Figure 1 is a view partly in elevation, but mainly in vertical section, of part of the structure of a motor vehicle at the front end thereof; Fig. 2, is a plan view and Fig. 3, a vertical section at right angles to Fig. 2, in line 3-3 of Fig. l, and Fig. 4, a section on line H of Fig. 1.

Referring to the drawings, 1 indicates a part of the side frame of a motor vehicle at the front end of such vehicle which frame 1s adapted to carry the body of the car and 2 lndicates a set of main leaf springs of an ordinary type. This set of springs is secured to the front I-beam axle 3 by means of clips 4 of the usual construction.

The shock absorbing device consists of a dash pot, the cylinder of which is connected to one of the members whose movement is to be checked and the piston rod of which is connected tothe other part to be checked. 5 is the cylinder of the dash pot and is adapted to contain a' body of oil 6, which, however, does not completely fill the cylinder, but leaves an air space above the same below the head of the cylinder. This cylinder has an attachable screw cap head 7, formed integral with which. or otherwise secured thereto is a ribbed bracket 8, adapted to bebolted to the frame 1 and having a lip 9 taking over the upper edge of the frame for the purpose of relieving the strain upon the securing bolt.

The screw cap head of the cylinder is provided with a stuffing box consisting of the hollow substantially cylindrical member 10 formed by flanges integral with the cap and extending on opposite sides thereof and having a conical inner end, and of a packing 11 and a screw plug 12 adapted to bear against the packing. Through the stuffing box is adapted to reciprocate a piston rod 13 carrying at its lowerend a piston 14:.

The piston 14. is provided with a horizontal head having apertures 15 therethrough adapted to permit the free passage of the oil and consequently the free unrestricted movement of the piston when the piston-rod is moved in one direction. This piston head is provided with an annular vertically elongated flange 16,. This flange is spaced slightly fromthe wall of the cylinder of the dash pot to permit and efl'ect a slow, gradual passage of the liquid past the piston when the latter moves downward relatively to the cylinder in its checking movement. The liquid in such movement is adapted to be forced slowly between the flange and the wall of the cylinder and the width of the passage between such parts determines the extent of rapidity of the relative movement of the piston and cylinder. The determination of the width of this space is fixed by suitably grinding the face of the flange of the piston. The elongated'flange provides a long friction surface against which the oil must pass and, therefore, obtains an effective retarding action while at the. same time such retarding action is gradual and the oil is permitted to slide past freely owing to the fact that the flange and wall of the cylinder arerelatively movable.

.At its lower end beyond the piston head the piston rod is provided with a screw plug 17 constituting a valve supporting member and on the outer smooth cylindrical surface of which-is mounted'a fiat disk valve 18 having a sliding movement thereon which is limited in one directionby the lower face of the-piston and in the other direction by a head 19 on said plug. This valve is adapted to close the apertures in the piston when the latter moves downward relatively to the cylinder, that is, in the separating movement of the body frame and axle, and

to automatically uncover said openings to permit the oil to pass freely therethrough less than that. of the liquid column cylinder whereby the total pressure in the air chamber. upon compression of the air .is less than that of the liquid column.

Mounted in the screw cap of the main cylnder 1san air pressure relief device consisting of a vertical hollow cylinder 21, preferably in the form of a screw plug and connecting with the interior of the cylinder above the body of oil. In this screw plug is mounted a hollow oil deflecting guard 'tube22 provided with perforations 23 and above this tube is a valve casing 2 1 having a'passageway' therethrough which is closed by a ball valve 25 underthe pressure of a spring 26- which spring is held infposition and the parts protected by means of a cap 27. The function of this device is to prevent oil from being forced out by the air pressure between the piston rod and the stuffing box, by relieving such air pressure above the body of oil. Any oil carried into the relief device along with the air will strike against the upper end of the guard tube and the air will escape through the openings therein and the oil will then fall back through the channel in the relief plug.

The upper end of the piston rod is provided with a forked end 28. Through the arms of such end passes a pivot pin 29 adapted to receive one end of a lever 30. A. fiat bent spring 31 has one end bearing against this lever and the other end bearing against a fixed pin 32 carried by the arms of the forked rod whereby the socket of the lever is held in close engagement with the pivot pin so as to take up any wear or lost motion between these parts and thus prevent wear and rattling at this connection.

The lever 30 is fulcrumed loosely on a shackle 33, pivoted to the frame member 1. It is pivotally and operatively connected near its connection with the piston rod to a vertical bar or rod 34 by means of a universal joint preferably in the form of a ball and socket whereby freedom of connection between the lever and the rod is provided enabling the lever and consequently the pis--- ton rod connected thereto to accommodate themselves to side swing in the parts connected by the two members of the shock absorber. Referring to this joint, 35 is the bolt passing through the lever 30 and provided at its inner end with a ball which engages on one side thereof a cone shaped block 36 mounted in one end of a cylindrical bearing casing 37 which is threaded on a head 38 carried at one end of the vertical rod 34. The lower end of the ball bears against a slidable block 39 which is pressed against by a spring 40 confined between a shoulder on said block and the head at the end of the rod and whereby a yielding pressure is exerted against the bearing blocks and ball to keep the same in contact and thus prevent wear and rattling due to lost motion. The lever 30 has a short arm between the piston rod and operating bar and a long arm between the fulcrum and the outer end of the lever, by which arrangement a stralght vertical movement of the piston rod is obtained.

At the lower end of the operating rod 34- is a loop 41 loosely engaging an eye 42 whereby a universal joint is provided. The eye 4-2 is bolted to a plate 43 which is clamped a ainst the under surface of the upper flange of the axle by means of the nuts on one of the clips 1. A resilient take-up device is mounted on the plate 43 to prevent lost motion between the loop and eye and this device consists of a sliding block 44: pressed against by a spring at mounted in a casing 4C7 which is secured to the plate 43.

The operation of the device as fol lows :In driving over smooth roads in which the vehicle will be subject to only slight shocks and jars the ordinary main springs are permitted to act freely both in the cushioning and rebound action of the springs without any retarding action by the dash. pot, since in the upward movement of the axle or approaching movement of the frame and axle the piston rod will be carried upward relatively to the cylinder and the cylinder relatively downward and in which movement the oil will flow freely through the apertures in the piston and in the rebound movement under such slight ordinary shocks, the reverse relative movement of the piston and cylinder will take place and the disk valve will close the apertures but the force of the piston will be exerted through the oil against the air in the auxiliary cylinder 20 which will not be compressed sufliciently in slight movements to offer any appreciable resistance, thus permitting the free and unrestricted response of the main springs to the rebound action. When a shock of considerable force occurs and the axle and frame approach one another the dash pot cylinder will move downward and the piston rod relatively upward in which movement there will also be a free and imrestricted action of the springs since the oil will escape freely through the openings in the piston. On the rebound ac tion, however, in the separating movement of the axle and frame the piston and cylinder will move toward one another with the piston being forced toward the bottom of the cylinder and the valve will close the openings tlurough the piston and the latter will thus exert a pressure against the oil and against the column of air in the auxiliary cylinder and this movement will be of sufficient force to compress the air and thus at ford a resistance to the movement of the piston which will elastically cushion the shock of the rebound action. The amount of the resistance is proportioned to the force of the shock. As the piston moves down the oil will gradually escape past the flange 16, the restricted passageway thus afforded serving to also check the relative movement of the piston and cylinder. Any air pressure that may accumulate in the main cylinder above the body of oil which may occur by the intake of air past the piston rod to fill the partial vacuum in the cylinder caused by the descent of the piston is permitted to escape through the relief valve and in this escape of the air any oil that may be carried along by the air will fall back through the guard tube 22 the air passing through the perforations 23.

lilaving thus described my invention, what I claim is:

1. A shock absorber for motor vehicles comprising a dash-pot operatively located between body and axle and having a liquid containing cylinder, and an auxiliary and relatively smaller air column cylinder in communication with the lower end of the liquid cylinder, a piston of less diameter than said dash pot mounted therein, and means to permit the free movement of the piston through the liquid in one direction and to retard it by the liquid in the other direction, causing the liquid to pass between the periphery of said piston and said dash pot.

2. A shock absorber for motor vehicles having a liquid containing dash pot cylinder secured to the body frame, a piston in said cylinder, a lever connected to the rod of said piston, and a connecting memberbetween the axle and said lever, pivotally joined to the latter at a point relatively near the piston rod.

3. A shock absorber for motor vehicles comprising a dash pot having a liquid containing cylinder, a piston and piston rod therein, an elongated lever fulcrumed on the body frame and connected at one end with the piston rod and a rod flexibly connected to said lever at a point near the piston rod and having means of flexible connection with the axle.

l. A shock absorber for motor vehicles having a dash pot provided with a liquid containing cylinder, means for securing the same to the body frame, a piston and piston rod in said cylinder, a lever fulcrun'ied on said frame and pivoted at one end to said piston rod, and a rod flexibly connected to the axle and to the lever between the fulcrum and piston rod connection and adjacent the latter.

In witness whereof, I have hereunto set my hand and seal at Indianapolis, Marion county, Indiana this lth day of October, A. D. nineteen hundred and sixteen.

CHARLES D. JENNEY. [n s.] Witnesses:

H. P. DooLIr'rLE,

A. C. Bros. 

